Siemens SITRANS LG270 Operating Instructions Manual page 77

Ʋ Bus specifications
Ʋ Data protocols
Max. transmission rate
Accuracy (according to DIN EN 60770-1)
Process reference conditions according to DIN EN 61298-1
Ʋ Temperature
Ʋ Relative humidity
Ʋ Air pressure
Installation reference conditions
Ʋ Min. distance to installations
Ʋ Vessel
Ʋ Medium
Ʋ Installation
Sensor parameter adjustment
Typical deviation - Interface measure-
ment
Typical deviation - Total level interface
measurement
Typical deviation - Level measurement
15 mm (0.591")
2 mm (0.079")
0
-2 mm (-0.079")
1
-5 mm (-0.197")
0,08 m
(3.15")
Fig. 43: Deviation SITRANS LG270 in rod version in water
1 Dead band - no measurement possible in this area
L Probe length
With interface measurement = 2.0
1)
Depending on the installation conditions, there can be deviations which can be rectified with an adaptation of
2)
the adjustment or a change of the measured value offset in the DTM service mode
The dead bands can be optimizes by a false signal suppression.
3)
PBD-51041066
Modbus Application Protocol V1.1b, Modbus over serial
line V1.02
Modbus RTU, Modbus ASCII, Levelmaster
19.2 Kbit/s
+18 ... +30 °C (+64 ... +86 °F)
45 ... 75 %
+860 ... +1060 mbar/+86 ... +106 kPa
(+12.5 ... +15.4 psig)
> 500 mm (19.69 in)
metallic, ø 1 m (3.281 ft), centric installation, process
fitting flush with the vessel ceiling
Water/Oil (dielectric constant ~2.0)
Probe end does not touch the vessel bottom
No gating out of false signals carried out
± 5 mm (0.197 in)
See following diagrams
See following diagrams
2)3)
0,3 m
(11.811")
SITRANS LG270 - Operating Instructions
L
1)
0,015 m
(0.591")
77